A circuit board

Abstract

This utility model belongs to the field of electrical equipment technology and discloses a circuit board, characterized in that it includes a circuit layer as an electromagnetic coil and an insulating layer. The insulating layer includes a core board insulating layer. The circuit layer and the insulating layer are alternately stacked from the inside to the outside starting from the core board insulating layer. A magnetic yoke layer made of magnetically conductive material is embedded inside the insulating layer. A through hole is opened in the insulating layer between two adjacent circuit layers, and the magnetic yoke layer is avoided at the through hole. This utility model embeds a high magnetic flux magnetic yoke layer inside the insulating layer to guide the magnetic field, achieving the technical effect of saving space and enhancing driving force. The magnetic yoke layer is designed to avoid connection with the conductive lines of the circuit board at the through hole, thus not increasing the line resistance and preventing the weakening of the original coil's driving force due to the introduction of magnetically conductive material.

Description

Technical Field

[0001] This utility model relates to the field of electrical equipment technology, and in particular to a circuit board. Background Technology

[0002] OIS motor is short for Optical Image Stabilization Motor, mainly used in camera modules of smartphones, cameras, and other devices. OIS motors adjust the position of the lens or image sensor to compensate for image blur caused by hand tremors or device movement, improving the stability and clarity of photos and videos.

[0003] A common OIS motor can be found in the structure disclosed in patent application number CN201710203714.6, which includes a housing, an upper gasket, an upper spring, an OIS coil assembly, electronic components, a magnet, a magnet holder, a lower spring, and a carrier. The housing and carrier are fitted together vertically, with other components housed within them. The carrier is typically rectangular, with the OIS coil assembly fixed to its outer perimeter, and various electronic components also mounted on the carrier. The OIS motor drives the lens or sensor module to move slightly to counteract vibrations through the interaction between the electromagnetic coil (OIS coil assembly) and the permanent magnet. The independent coil with a magnetic yoke structure occupies a relatively large space.

[0004] To meet the ultra-small size requirements of voice coil motors for electronic devices with cameras such as smartphones, the applicant proposed an improved structure in Chinese invention application CN202211331530.5 entitled "An OIS Motor Coil Assembly and Preparation Method". The improved structure uses a circuit board with printed flat coils to replace the traditional structure in which the coil is sleeved on the carrier. The OIS coil assembly is directly embedded into the PCB through circuit printing process to reduce additional components.

[0005] However, although the coil structure has been upgraded to a flat type to save space, in order to meet the needs of different products, it is still necessary to provide a solution that can further enhance the driving force of the motor, thereby making improvements in many aspects such as saving space, enhancing driving force, and ensuring signal integrity. Utility Model Content

[0006] The technical problem to be solved by this utility model is to propose a circuit board that saves space and enhances driving force in light of the above-mentioned technical status.

[0007] The technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows: a circuit board, characterized in that it includes a circuit layer as an electromagnetic coil and an insulating layer, the insulating layer including a core board insulating layer, the circuit layer and the insulating layer are alternately stacked from the inside to the outside starting from the core board insulating layer, and a magnetic yoke layer made of magnetic conductive material is embedded inside the insulating layer; a through hole is opened in the insulating layer between two adjacent circuit layers, and the magnetic yoke layer is positioned at the through hole.

[0008] Compared with existing technologies, the advantages of this invention are that the OIS coil is directly embedded into the PCB as a circuit, using the circuit layer as the electromagnetic coil, resulting in a more compact overall structure. Simultaneously, a high-flux magnetic yoke layer is embedded inside the insulating layer to guide the magnetic field, achieving both space saving and enhanced driving force. This helps improve the performance of the OIS motor, enabling faster and more precise adjustment of the lens position during optical image stabilization. Furthermore, the magnetic yoke layer employs a recessed design at the vias to ensure it does not connect to the conductive lines of the circuit board, thus not increasing circuit resistance and preventing the introduction of magnetic material from weakening the original coil's driving force.

[0009] To further enhance the driving force, preferably, the insulating layer includes a core insulating layer, an interlayer insulating layer and an outer insulating layer, with a magnetic yoke layer embedded inside the core insulating layer and the interlayer insulating layer, and a magnetic yoke layer being pressed, coated or bonded to the surface of the outer insulating layer.

[0010] Preferably, the magnetically conductive material is a soft magnetic ferrite or a hard magnetic ferrite. The general chemical formula of ferrite is typically MO·Fe₂O₃, where M is a divalent metal ion (such as Mn). 2+ Zn 2+ Ni 2+ Ba 2+ 、Sr 2+ (etc.). A typical example of soft magnetic ferrites is manganese-zinc ferrite (MnZn), chemical formula example: Mn 0.5 Zn 0.5 Fe2O4, and nickel-zinc ferrite (NiZn), are suitable for applications such as:

[0011] a) High-frequency transformers: switching power supplies, wireless chargers;

[0012] b) Inductors: Filtering and energy storage components;

[0013] c) Electromagnetic interference (EMI) suppression: ferrite beads, common mode chokes;

[0014] d) Microwave devices: isolators, circulators (utilizing the gyromagnetic effect).

[0015] A typical example of hard magnetic ferrites is barium ferrite (BaFe). 12 O 19), Strontium ferrite (SrFe) 12 O 19 ) etc., suitable for application in:

[0016] a) Electric motors and generators: car starter motors, power tools;

[0017] b) Loudspeakers and sensors: Core materials for magnetic circuit systems;

[0018] c) Magnetic separation technology: magnetic adsorption in industrial wastewater treatment;

[0019] d) Emerging fields: 5G communication high-frequency components, new energy vehicle motors, magnetic resonance imaging (MRI) equipment.

[0020] Preferably, the magnetically conductive material is bulk ferrite, and the bulk ferrite forms the first magnetic yoke layer;

[0021] The first magnetic yoke layer is embedded in the core board insulation layer and the interlayer insulation layer, and is pressed against the surface of the outer insulation layer.

[0022] Preferably, the magnetic material is powdered ferrite, which is incorporated into the insulating material to form a second magnetic yoke layer.

[0023] The second magnetic yoke layer is embedded in the core board insulation layer and the interlayer insulation layer, and is disposed on the surface of the outer insulation layer.

[0024] Preferably, the magnetically conductive material is powdered ferrite;

[0025] Powdered ferrite is coated or PVD sprayed into the core board insulation layer, the interlayer insulation layer, and the surface of the outer insulation layer to form a third magnetic yoke layer.

[0026] Preferably, the magnetically conductive material is a sheet-like or thin-film ferrite, and the sheet-like or thin-film ferrite forms a fourth magnetic yoke layer;

[0027] The fourth magnetic yoke is laminated and embedded within the core board insulation layer and the interlayer insulation layer, and is disposed on the surface of the outer insulation layer.

[0028] Preferably, the magnetically conductive material is rod-shaped ferrite, and the rod-shaped ferrite forms the fifth magnetic yoke layer;

[0029] The fifth magnetic yoke layer is vertically or horizontally embedded within the core board insulation layer and the interlayer insulation layer.

[0030] When the circuit board is used in an OIS motor, preferably, the thickness of the magnetic yoke layer is in the range of 20-50 μm.

[0031] When the circuit board is used for high-power wireless charging, the thickness of the magnetic yoke layer ranges from 100 to 200 μm. Attached Figure Description

[0032] Figure 1 This is a cross-sectional schematic diagram of Embodiment 1 of the present invention;

[0033] Figure 2 This is a cross-sectional schematic diagram of the core board insulation layer and inner circuit layer of Embodiment 1 of this utility model;

[0034] Figure 3 To and Figure 2 Corresponding planar diagram;

[0035] Figure 4 This is a schematic diagram of the structure of Embodiment 2 of the present invention;

[0036] Figure 5 This is a schematic diagram of the structure of Embodiment 3 of this utility model;

[0037] Figure 6 This is a schematic diagram of the structure of Embodiment 4 of this utility model;

[0038] Figure 7 This is a schematic diagram of the structure of Embodiment 5 of the present invention;

[0039] Figure 8 This is a structural schematic diagram of Embodiment 6 of the present invention. Detailed Implementation

[0040] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0041] Example 1

[0042] like Figures 1-3 The diagram shows a preferred embodiment of a circuit board according to this utility model.

[0043] The circuit board structure of this embodiment includes a circuit layer 10 and an insulating layer 20. The circuit layer 10 contains printed coil-type circuits as electromagnetic coils, replacing traditional winding coils. The insulating layer 20 can be divided into a core insulating layer 21, an interlayer insulating layer 22, and an outer insulating layer 23. The circuit layer 10 and the insulating layer 20 are stacked alternately from the inside to the outside, starting from the core insulating layer 21. The specific stacking sequence in this embodiment is as follows: Figure 1 As shown, the core board insulation layer 21 is located in the middle of the circuit board. An inner circuit layer 11 is disposed on the upper and lower surfaces of the core board insulation layer 21, respectively. An interlayer insulation layer 22 is disposed outside each inner circuit layer 11, an outer circuit layer 12 is disposed outside each interlayer insulation layer 22, and an outer insulation layer 23 is disposed outside each outer circuit layer 12. The core board insulation layer 21 and the interlayer insulation layer 22 are made of epoxy resin, and the outer insulation layer 23 is made of ink.

[0044] In this embodiment, the circuit board has four circuit layers 10. The number and distribution of coils in the same layer can be manufactured as needed. The number of coil turns can be achieved through exposure and development processes, thereby embedding the OIS coil directly into the PCB in the form of a circuit. The overall structural layout is more compact, reducing the space occupied by additional components and achieving a space-saving effect. In addition, the circuit board can also be designed with more or fewer circuit layers 10. When the circuit board has only two circuit layers 10, the insulating layer 20 only includes the core insulating layer 21 and the outer insulating layer 23, excluding the interlayer insulating layer 22. When the circuit board has four or more circuit layers 10, the insulating layer 20 includes a greater number of interlayer insulating layers 22, while the number of core insulating layers 21 and outer insulating layers 23 remains unchanged.

[0045] In this embodiment, a magnetic yoke layer 3 made of magnetically conductive material is embedded inside the insulating layer 20. The embedded high-magnetic-flux magnetic yoke layer 3 can guide the magnetic field, achieving the technical effect of saving space and enhancing driving force, which helps to improve the performance of the OIS motor. A through-hole 4 is formed in the insulating layer 20 between two adjacent circuit layers 10, and the magnetic yoke layer 3 is positioned away from the through-hole 4. Figure 2 As shown, this ensures that it will not be connected to the conductive lines of the circuit board, thus not increasing the line resistance, and therefore will not weaken the driving force of the original coil due to the introduction of magnetic material.

[0046] This circuit board structure is also applicable to other fields. The magnetic yoke layer 3 can be made of various high magnetic flux materials. In this embodiment, the magnetically conductive material is soft magnetic ferrite or hard magnetic ferrite. The general chemical formula of ferrite is generally MO·Fe2O3, where M is a divalent metal ion (such as Mn). 2+ Zn 2+ Ni 2+ Ba 2+ 、Sr 2+ (etc.). A typical example of soft magnetic ferrites is manganese-zinc ferrite (MnZn), chemical formula example: Mn 0.5 Zn 0.5 Fe2O4, and nickel-zinc ferrite (NiZn), are suitable for applications such as:

[0047] a) High-frequency transformers: switching power supplies, wireless chargers;

[0048] b) Inductors: Filtering and energy storage components;

[0049] c) Electromagnetic interference (EMI) suppression: ferrite beads, common mode chokes;

[0050] d) Microwave devices: isolators, circulators (utilizing the gyromagnetic effect).

[0051] A typical example of hard magnetic ferrites is barium ferrite (BaFe). 12 O 19), Strontium ferrite (SrFe) 12 O 19 ) etc., suitable for application in:

[0052] a) Electric motors and generators: car starter motors, power tools;

[0053] b) Loudspeakers and sensors: Core materials for magnetic circuit systems;

[0054] c) Magnetic separation technology: magnetic adsorption in industrial wastewater treatment;

[0055] d) Emerging fields: 5G communication high-frequency components, new energy vehicle motors, magnetic resonance imaging (MRI) equipment.

[0056] In this embodiment, the magnetic material used is bulk soft magnetic ferrite, which forms the first magnetic yoke layer 3a. The first magnetic yoke layer 3a is embedded in the core board insulation layer 21, and is applied to the surface of the outer insulation layer 23 as a reinforcing element, either by pressing or bonding with adhesive layer 6, or a combination of both, according to the shape design of the circuit board product. During design and production, any one or more of the first magnetic yoke layers 3a can be placed at the aforementioned locations on the circuit board according to actual needs. The more first magnetic yoke layers 3a are placed, and the closer they are to the permanent magnet, the stronger the driving force they provide. The placement of the magnetic yoke layers 3a can be flexibly adjusted based on this principle. The first magnetic yoke layer 3a actively opens a window to avoid displacement during the embedding stage; its window dividing line 5 can be referenced. Figure 3 As shown, this avoids additional operations during subsequent processing while ensuring precise alignment of the magnetic yoke layer 3.

[0057] When the circuit board is used in the OIS motor of a mobile phone, the thickness of the magnetic yoke layer 3 ranges from 20 to 50 μm.

[0058] In addition, the circuit board of this embodiment can also be used for high-power wireless charging, in which case the thickness of the magnetic yoke layer 3 is in the range of 100-200μm.

[0059] Example 2

[0060] The structure of this embodiment is as follows: Figure 4 As shown, the difference between this embodiment and embodiment 1 is that the first magnetic yoke layer 3a is embedded in the core board insulation layer 21 and the interlayer insulation layer 22, and is pressed against the surface of the outer insulation layer 23.

[0061] Example 3

[0062] The structure of this embodiment is as follows: Figure 5As shown, the difference between this embodiment and Embodiment 1 is that the magnetic material used in this embodiment is powdered soft magnetic ferrite, which is incorporated into the insulating material to form a second magnetic yoke layer 3b. The second magnetic yoke layer 3b is embedded in the core board insulating layer 21 and the interlayer insulating layer 22, and is disposed on the surface of the outer insulating layer 23.

[0063] Example 4

[0064] The structure of this embodiment is as follows: Figure 6 As shown, the difference between this embodiment and embodiment 1 is that the magnetic material used in this embodiment is powdered soft magnetic ferrite. The powdered ferrite is coated or PVD sprayed in the core board insulation layer 21, the interlayer insulation layer 22, and the surface of the outer insulation layer 23 to form a third magnetic yoke layer 3c.

[0065] Example 5

[0066] The structure of this embodiment is as follows: Figure 7 As shown, the difference between this embodiment and embodiment 1 is that the magnetic material used in this embodiment is sheet-like / film-like soft magnetic ferrite, and the sheet-like or film-like ferrite forms the fourth magnetic yoke layer 3d; the fourth magnetic yoke layer 3d is pressed and embedded in the core board insulating layer 21 and the interlayer insulating layer 22, and is disposed on the surface of the outer insulating layer 23.

[0067] Example 6

[0068] The structure of this embodiment is as follows: Figure 8 As shown, the difference between this embodiment and embodiment 1 is that the magnetic material used in this embodiment is rod-shaped soft magnetic ferrite, and the rod-shaped ferrite forms the fifth magnetic yoke layer 3e; the fifth magnetic yoke layer 3e is vertically or horizontally embedded in the core board insulation layer 21 and the interlayer insulation layer 22.

Claims

1. A circuit board, characterized in that, The circuit includes a circuit layer (10) and an insulating layer (20) that serve as an electromagnetic coil. The insulating layer (20) includes a core board insulating layer (21). The circuit layer (10) and the insulating layer (20) are stacked alternately from the inside to the outside starting from the core board insulating layer (21). A magnetic yoke layer (3) made of magnetic conductive material is embedded inside the insulating layer (20). A through hole (4) is provided in the insulating layer (20) between two adjacent circuit layers (10). The magnetic yoke layer (3) is positioned at the through hole (4).

2. The circuit board according to claim 1, characterized in that, The insulation layer (20) includes a core board insulation layer (21), an interlayer insulation layer (22) and an outer insulation layer (23). A magnetic yoke layer (3) is embedded inside the core board insulation layer (21) and the interlayer insulation layer (22), and the magnetic yoke layer (3) is pressed, bonded or coated on the surface of the outer insulation layer (23).

3. The circuit board according to claim 1, characterized in that, The magnetically conductive material is either soft magnetic ferrite or hard magnetic ferrite.

4. The circuit board according to claim 2, characterized in that, The magnetically conductive material is bulk ferrite, and the bulk ferrite forms the first magnetic yoke layer (3a); The first magnetic yoke layer (3a) is embedded in the core board insulation layer (21) and the interlayer insulation layer (22), and is pressed against the surface of the outer insulation layer (23).

5. The circuit board according to claim 2, characterized in that, The magnetic material is powdered ferrite, which is incorporated into the insulating material to form a second magnetic yoke layer (3b). The second magnetic yoke layer (3b) is embedded in the core board insulation layer (21) and the interlayer insulation layer (22), and is disposed on the surface of the outer insulation layer (23).

6. The circuit board according to claim 2, characterized in that, The magnetically conductive material is powdered ferrite; Powdered ferrite is coated or PVD sprayed into the core board insulation layer (21), the interlayer insulation layer (22), and the surface of the outer insulation layer (23) to form a third magnetic yoke layer (3c).

7. The circuit board according to claim 2, characterized in that, The magnetically conductive material is a sheet-like or thin-film ferrite, and the sheet-like or thin-film ferrite forms a fourth magnetic yoke layer (3d); The fourth magnetic yoke layer (3d) is pressed and embedded in the core board insulation layer (21) and the interlayer insulation layer (22), and is disposed on the surface of the outer insulation layer (23).

8. The circuit board according to claim 2, characterized in that, The magnetically conductive material is rod-shaped ferrite, and the rod-shaped ferrite forms the fifth magnetic yoke layer (3e); The fifth magnetic yoke layer (3e) is vertically or horizontally embedded within the core board insulation layer (21) and the interlayer insulation layer (22).

9. The circuit board according to claim 1, characterized in that, The thickness of the magnetic yoke layer (3) ranges from 20 to 50 μm.

10. The circuit board according to claim 1, characterized in that, The thickness of the magnetic yoke layer (3) ranges from 100 to 200 μm.

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